Samuel jeffs



(No Model.)

' S.JEFPS.

GAGE FOR SCREW CUTTING LATHES; No. 1f/0.142;v

Patented Mar. 1, 1892.

4IMEI-WCM? v Samuel Jffw if?? M Y ,5M @ffy UNITED STATES;

"PATnrrr` OFFICE. y

SAMUEL JEFES, OF ERIE, PENNSYLVANIA, ASSIGN OR OF ONE-HALF TO SOLON C.LONG, lOF SAME PLACE. y

GAGE FOR SCREW-CUTTING LATHES.

SPECIFICATION forming part of Letters Patent N o. 470,142, dated March1, 1892. Applicatidn led September 4:, 1891. v Serial No. 404,775. (Nomodel.)

T0 all `whom t may concern:

Be itknown that I, SAMUEL JEFFs, a citizen of England, residing at thecity of Erie, in the county of Erie and State of Pennsylvania, haveinvented certain new and useful Improvements in Screw-Cutting Gages forEngine-Lathes; and I do hereby declare the following to be a full,clear, and exact descrip-l tion of the invention, such as will enableothers skilled in the art to which it appertains to make and use thesame, reference being had to the accompanying drawings, and to theletters of reference marked thereon, forming part of this specification.

My invention consists in the improvements in screw-cutting gages forengine-lathes hereinafter set fort-h and explained, and illustrated inthe accompanying drawings, in which- Figure l is a side elevation of aportion of my improved screwcutting gage detached from the lathe. Fig.2is afront elevation ofthe same. Fig. 3 is a front elevation of asection of an engine-lathe with my improved screwcutting gage thereon.Fig. 4 is a detail view on line cc a; in Fig. l.

In the construction shown in the drawings of my improved screw-cuttinggage, A is a section of the bed of an engine-lathe, B the tool-carriage,and C the feed-screw of the same. To the carriage B, I secure adetachable horizontal scale D, preferably divided into inches,half-inches, dac., in the usual manner. On the feed-screw C, I place thetraveling portion of my device, consisting of a vertical bar E, havingon the inside face thereof a semicircular arm F, which' projects overthe upper half of the screw C and rests thereon. The upper end of thebar E is also provided with a pointer e, which travels close to thehorizontal scale D. In the vertical bar E below the arm F, I' cut avertical slot cl, in which an inwardly-projecting arm G, which encirclesthe lower half of the screw C, is secured so as to move vertically inthe slot d.. This arm G is provided with a screw-thread f, which isadapted to engage with the screw C when raised up into contacttherewith, as illustrated in Fig. 4. On the outside of the upright barE, I mount a double crank H on a bearing h just below the lower end ofthe slot d, and from the crank H aconnecting-rod I extends upward and ispivoted to one of the lugs .I on the arm G, operating in the slot d, andby means whereof it is movably secured to the upright bar E, so thatwhen the handle K of the crank I-I is raised to a vertical position itraises the arm G up into contact with the screw O and when the crank I-Iis turned downward the arm G is moved downward out of contact with thefeed-screw C, as illustrated by the dotted lines in Fig. l. By thismeans the upright bar E can be detached from the feed-screw C and movedlongitudinally thereon, as desired, and also thrown into engagementtherewith at any point desired.

In operation the upright bar E is moved vaway from the carriage towardthe end b of the scale D and engaged with the feed-screw C when thepointer c is opposite one of the division-marks on the scale D. The toolsecured on the carriage B being then started into the thread to be cuttravels the length thereof, the carriage being then released and movedback to the commencement of the thread, and again started into thethread when the pointer e is opposite one of the divisions on the scaleD, this process being repeated until the thread to be cut is completed.In case, however, during the completion of the thread the bar E hastraveled far enough on the screw C to contact with the carriage B beforethe thread is fully completed then the vertical bar E is detached fromthe screw C and moved back toward the end b of the scale and againengaged therewith when the pointer is opposite one of the divisionsthereof, when the work'is again proceeded with, as before. The scale Dcan be with equal facility secured to the opposite side of the carriageand the traveling upright bar E then placed on the screw C at theopposite side of the carriage B with equal facility, if desired.

Having thus fully described my invention, so as to enable others toconstruct and operate the same, what I claim as new, and desire tosecure by Letters Patent of the United States, is-

l. The combination, in ascrew-cutting gage for engine-lathes, of alongitudinal scale secured to the tool-carriage of the lathe, with atraveling vertical bar having apointeron the ICO upper end thereofdetachably secured to the feed-screw of the lathe, substantially as andfor the purpose set forth.

2. The combination, in a screw-cuttinggage for engine-lathes, of alongitudinal scale secured to the tool-carriage of the lathe, a verticalbar carrying a pointer on the upper end thereof and having an armthereon adapted to encircle the upper half of the feed-screw of thelathe, with a vertically-movable arm on the upright bar, having ascrew-thread therein adapte i, to encircle the lower half of thefeedscrew and be engaged therewith, substantially as and for the purposeset forth.

3. The combination, in a screw-cutting gage for engine-lathes, of avertical bar, as E, having a pointer, as e, thereon, and anupwardlyprojecting arm, as F, on said vertical bar E, adapted toencircle the upper half of the feedscrew of an engine-lathe and besupported thereon, with a movable arm, as G, mounted in a vertical slotin the upright bar E and having a screw-thread adapted to encircle thelower half of the lathe feed-screw and engage therewith, and crankmechanism, as I-I, for moving the arm G into and out of engagement withthe feed-screw of the lathe, substantially as and for the purpose setforth.

' In testimony whereof I affix my signature in presence of twowitnesses.

y SAMUEL JEFFS.

Witnesses:

S. C. LONG, WM. P. HAYES.

